Let´s say I have two tables, "Garden" and "Flowers". There is a 1:n-relationship between these tables, because in a garden can be many flowers. Is it possible to write an SQL query which returns a result with the following structure:
GardenName Flower1Name Flower2Name .... (as long as there are entries in flowers)
myGarden rose tulip
CREATE TABLE #Garden (Id INT, Name VARCHAR(20))
INSERT INTO #Garden
SELECT 1, 'myGarden' UNION ALL
SELECT 2, 'yourGarden'
CREATE TABLE #Flowers (GardenId INT, Flower VARCHAR(20))
INSERT INTO #Flowers
SELECT 1, 'rose' UNION ALL
SELECT 1, 'tulip' UNION ALL
SELECT 2, 'thistle'
DECLARE @ColList nvarchar(max)
SELECT @ColList = ISNULL(@ColList + ',','') + QUOTENAME('Flower' + CAST(ROW_NUMBER() OVER (ORDER BY (SELECT 0)) AS VARCHAR))
FROM #Flowers WHERE GardenId = (
SELECT TOP 1 GardenId
FROM #Flowers
ORDER BY COUNT(*) OVER (PARTITION BY GardenId) DESC
)
EXEC (N'
;WITH cte As
(
SELECT *, ''Flower'' + CAST(ROW_NUMBER() OVER (PARTITION BY GardenId ORDER BY (SELECT 0)) AS VARCHAR) RN
FROM #Flowers F
)
SELECT Name,' + @ColList + N'
FROM cte
JOIN #Garden g ON g.Id = GardenId
PIVOT (MAX(Flower) FOR RN IN (' + @ColList + N')) Pvt')
DROP TABLE #Garden
DROP TABLE #Flowers
Returns
Name Flower1 Flower2
-------------------- -------------------- --------------------
myGarden rose tulip
yourGarden thistle NULL
Look at using Pivot in SQL Server. Here is a good link that goes over how it works:
http://www.kodyaz.com/articles/t-sql-pivot-tables-in-sql-server-tutorial-with-examples.aspx
Ok, i think i got it working. Try this:
with temp as
(
select 'myGarden' as name, 'test1' as flower
union
select 'myGarden','test2'
union
select 'myGarden','test5'
union
select 'abeGarden','test4'
union
select 'abeGarden','test5'
union
select 'martinGarden', 'test2'
)
select* from temp
pivot
(
max(flower)
for flower in (test1,test2,test3,test4,test5)
) PivotTable
You could also make the values in the in clause dynamic. Since this is a CTE i can't in my example.
Flower1 etc with the information about the flower contained in the row as per the OP's example.Dynamic SQL with a cursor is the only way I can think of, and it won't be pretty.
If you only want the results for one garden at a time this would give you the data:
select gardenName from tblGarden where gardenid = 1
Union ALL
select tblFLowers.flowerName from tblFlowers where gardenid = 1
